The new movie "Frost/Nixon" offers us the pleasure, more common in the theater, of watching two excellent actors simply being, well, excellent. The film is mostly talk, but it's sharp, punchy talk, and the picture is sometimes thrilling to watch.

"Frost/Nixon," which was written by Peter Morgan, did in fact start out as a stage play. It debuted in London in 2006, and had a short run on Broadway last year. Frank Langella and Michael Sheen, the stars of both productions, reprise their roles in the film with a combination of fresh endeavor and easy intimacy with the material. Sheen, so breezy and appealing as Tony Blair in "The Queen," here slips smoothly into the role of David Frost, the English talk-show host and infotainment personality who, as portrayed in "Frost/Nixon," is a bit of a fop and a bit of a poseur, but clawingly ambitious at his core. In 1977, Frost conducted a series of four two-hour interviews with ex-President Richard Nixon, who'd been driven from office three years earlier by the Watergate scandal. Nixon, exiled in shame on his palmy estate in San Clemente, California, agreed to the interviews out of a powerful drive to redeem himself in the public eye. And there was the money, too: $600,000 that Frost, desperate to reinvent himself as a real journalist, didn't actually have.

In the movie — directed with unshowy expertise by Ron Howard — Nixon himself, in the flesh, turns out to be something of a surprise. In Langella's characterization, he's a tall, hulking figure with a familiar jowly droop — but not at all the fool that Frost and his team had expected. One of Frost's researchers, James Reston, Jr. (Sam Rockwell), is an unyielding Nixon-hater, still incensed that the man escaped impeachment and prosecution for his misconduct in office by resigning it. "I'd like to give Richard Nixon the trial he never had," Reston says. And indeed, that's what Frost wants, too — a final accounting, with the former president forced at last to admit his misdeeds.

But over the course of the first three interviews, Nixon proves to be, even more than Frost himself, a master of television and a most cagey adversary. Sitting down for their initial encounter, Nixon asks Frost, just as the cameras are about to roll, "Did you have a pleasant evening last night?" Frost did. Then Nixon slyly says, out of nowhere, "Did you do any fornicating?" Frost is seriously rattled, and never recovers control of the interview, as Nixon drones on and on, dragging out his answers to eat up their allotted time.

Then, late on the night before the last interview, Nixon calls Frost at his hotel. He's been drinking. He says he's been reading through a dossier on Frost, and knows his career is flagging. He believes the two of them have something in common — a resentment at always being slapped down by the smart people of the world, the intellectuals and the well-born. They're both seeking a sort of public-relations salvation from the darkness that's enveloping their careers. "Isn't that why we're here," Nixon asks, "looking for a way back to the sun?"

The next day, Frost rallies. Determined to dominate the final interview, he presses Nixon unrelentingly for an admission of his misconduct in office — and Nixon finally relents. But, he insists, "They were mistakes of the heart, not of the head. ... I brought myself down."

The Watergate scandal was a long time ago, and Frost's interviews with Nixon, although they elevated Frost to a new level of professional distinction, weren't really the historic events that the play, and now the movie, attempt to make them. But the excitement of the film is in watching two wily adversaries, desperate for personal and professional redemption, going at each other in the great world-media arena. It's like the dawn of a brawling new age — the one in which we still live.